In recent years the need to make seat belts closely fit the front seat occupants of a vehicle has become more important because of the increased emphasis on safety. Seat belts have also become standard equipment for rear seat passengers. Front seat belt arrangements of the following type are known: A seat belt is held in a holding condition for a vehicle passenger and in a releasing condition to permit a passenger to enter and exit the vehicle in timed relation to the opening and closing of the door. In a vehicle seat provided with such a seat belt arrangement, it is a conventional to provide an emergency lock type retractor for winding and unwinding the seat belt which is installed through a fixed bracket mounted near the rear side of the seat cushion.